In the construction of a hollow fibre separatory device a large number of factors need to be considered, the complexity of which varies dependently of the nature of the fluid to be treated, and the size of the bores of the hollow fibres. For example, if the fluid to be treated is blood, which in conventional devices is normally passed through the insides of a multitude of very fine hollow fibres, care needs to be taken to avoid so-called regions of stasis which can lead to clotting and blocking of a significant number of hollow fibres. An approach to this difficulty is to construct the device in such a fashion that turbulence will prevail in the blood immediatly prior to entry into hollow fibre openings. In known devices, a reservoir of relatively small volume is defined between an end casing section and the face of a sealing material at which face hollow fibres define open ends. Such hollow fibre devices function with varying efficiency and all require that blood be heparinized to reduce the inclination for blood to clot in the hollow fibre device.
It is an object of the present invention to provide an improved hollow fibre separatory device in which fluid to be treated, and in particular blood, will be subjected to less changes or less abrupt changes of its dynamic state in its progress from a fluid supply line, into the said reservoir and into hollow fibres. Stated in another fashion, this object of the invention is concerned with reducing the abruptness of acceleration which fluid particles are subjected to in their progress from the reservoir into hollow fibres. Related to this object is the further object to reduce potential regions of a form of stasis which can occur at regions which are irregular as related to fluid flow directions.
A further and independent object of the present invention is concerned with facilitating passage of fluid into (or out of) the insides of hollow fibres.
Yet a further object of the invention is related to a construction in which the potential of stagnant regions developing in the reservoir is reduced. More particularly, a construction of the invention includes the consideration of endeavouring to maintain fluid flow across all faces to which it is exposed at substantially similar rates.